Tanner Hall, Starring Rooney Mara, is Boarding School Via Instagram

Tanner Hallis a cool-girl boarding-school movie, which is to say that nobody sings in unison. There are no wizards, and there is no butter beer. And there are no besweatered guys bellowing Carpe Diem!at passersby. Instead, the film—which debuted at TIFF in 2009, and makes its theatrical debut today—is a gentle, artful entry into the genre, a tone-poem about the ungainliness of being 17. It’s more The Group than School Ties, and is filtered through a fresh, Instagram-y palette of apple reds, crunchy-leaf browns, and tweed-jumper grays.

No surprise that it’s the product of two sisterly friends—the film was co-written and co-directed by Francesca Gregorini and Tatiana Von Furstenberg, best friends since they themselves were 17. Rooney Mara, Georgia King, Brie Larson, and Amy Ferguson play the main gang of four girls, but the movie also features Amy Sedaris, Chris Kattan, and Tom Everett Scott, winsome as a townie dad and Mara’s verboten love interest. The movie has a timeless aesthetic, helped by the fact that it’s mostly cell-phone-free—sweet relief at a time when most coming-of-age tales use the rat-a-tat-tatting of venomous BlackBerry messages to convey plot. Gregorini and Von Furstenberg wrote the script in part as poetic response to the “bitchy sarcasm” that’s become the dominant strain of dialogue in female-centric films, Von Furstenberg says. “[O]ur teen girls are capable, and I don’t think the stuff that’s out there is serving them,” she says, as the mother of a middle-schooler. “They’re capable of much more complexity and poetry—the materialism of today’s culture is very one-note.” To simulate the kind of girl-bonding that she and Gregorini enjoyed as kids, the pair had the actresses stay together, cooking dinner for them on occasion and yanking wardrobe options from their own closets. “We wanted them to get into mischief,” she says.

As for Mara, Tanner Hall marks the leading-lady debut of the 26-year-old in a feature, and her career is soaring. Her memorable scenes as Mark Zuckerberg’s ex in The Social Networkhelped land her the coveted role of Lisbeth Salander in David Fincher’s The Girl with the Dragon Tattoo, and while she’s nearly unrecognizable in her Lisbeth duds, her clear-eyed expressions and Bette Davis bone structure make her the perfect face for Tanner Hall’s contemplative, willowy Fern. “She has an internal dignity and an internal reservation—she’s not look at me, look at me,” Von Furstenberg says of Mara’s on-camera poise. “But still water runs deep, and you want to know what she’s thinking.”

Tanner Hall debuts in limited release on September 9. Watch the trailer here.